1. Field of the Invention
The present invention relates to a particular electronic flash arrangement adapted for use with cameras of the type having a last flash inhibit feature and more particularly to an electronic flash accessory which is adapted to enable a camera of the type having a last flash inhibit feature in response to a predetermined event relative to the readying of the flash accessory in expectation of the commencement of a photographic exposure cycle involving an artificially illuminated subject.
2. Description of the Prior Art
Both the Polaroid SX-70 Land Camera and the newly introduced pronto! Camera, made and sold by the Polaroid Corporation of Cambridge, Massachusetts, U.S.A., are adapted to make photographs automatically either by ambient light or with the aid of a flash lamp array. For this purpose, the camera is provided with an accessory socket in the shutter and lens board housing which will accept a part from a flash lamp array. The flash lamp array includes five flash lamps in one array and five in another so that five sequential exposures can be made, each with a different bulb, when the array is inserted in the socket in either position. The remaining five lamps can be sequentially used by removing the flash array, and putting it back in facing the opposite direction.
The camera is provided with a sequencing circuit to select the next unfired bulb for energization, and to sequence the camera circuits which operate the shutter, control the mirror and operate the processing rolls.
The camera may also include a so-called "last flash inhibit feature" whereby the exposure system detects the expenditure of the last flash lamp scheduled to be fired within the flash lamp array and automatically inhibits the performance of an automatic photographic exposure cycle. Such an inhibiting feature is fully described in a copending Application for U.S. patent Ser. No. 482,379 now U.S. Pat. No. 4,005,449 issued on Jan. 25, 1977, entitled "Flash Photographic System With Camera Inhibit Feature" by Seymour Ellin filed June 24, 1974.
It is highly desirable to extend the capabilities of the Polaroid SX-70 Land Camera as well as the new Polaroid Pronto! Camera for use with an electronic flash. One type of strobe suitable for use with Polaroid's SX-70 Land Camera is disclosed in an Application for U.S. patent Ser. No. 679,698 entitled "Compact Accessory Strobe For Camera With Battery Enclosed Film Pack," filed Apr. 23, 1976 in common assignment herewith. Connection of the aforementioned strobe to the Polaroid SX-70 Land Camera of the type having the last flash inhibit feature exerts no operative influence on the automatic electronic exposure control system of the camera. In other words, connection of the aforementioned strobe to the SX-70 Land Camera will enable the camera upon actuation by the user to perform its automatic exposure cycle regardless of whether the strobe is in a state of readiness to provide adequate artificial illumination.
A camera which is adapted solely for use with a detachable electronic flash accessory additionally includes a feature for inhibiting the camera exposure control system until the charging of the flash unit is initiated by pressing a button and the flash unit is fully charged at which time the camera is automatically enabled to make a flash exposure. Such a camera and detachable electronic flash unit are fully described in a copending Application for U.S. patent Ser. No. 698,715 entitled "Camera With Detachable Electronic Flash Unit And Exposure Control System Therefore", by Edwin H. Land and Richard C. Kee, filed June 22, 1976 in common assignment herewith. The camera and strobe arrangement of this invention, however, do not provide for ready interchangeability with the aforementioned flash lamp array.
Therefore, it is a primary object of this invention to provide an electronic flash accessory for use with cameras of the type having a flash lamp receiving socket as well as a last flash inhibit feature whereby the strobe unit exerts an operative influence on the automatic control system of the camera.
It is another object of this invention to provide an electronic flash accessory for use with Polaroid's SX-70 Land Cameras and New Pronto! Cameras of the type having a last flash inhibit feature whereby operation of the automatic exposure control systems of these cameras is inhibited until the occurrence of some predetermined event relative to the readying of the flash accessory in expectation of the commencement of a photographic exposure cycle involving an artificially illuminated subject.
Other objects of the invention will in part be obvious and will in part appear hereinafter. The invention accordingly comprises the mechanism and system possessing the construction, the combination of elements and the arrangement of parts which are exemplified in the following and detailed disclosure.